Global and local cortical folding alterations are associated with neurodevelopmental subtype in bipolar disorders: a sulcal pits analysis

BACKGROUND

Analyzing cortical folding may provide insight into the biological underpinnings of neurodevelopmental diseases. A neurodevelopmental subtype of bipolar disorders (BD-ND) has been characterized by the combination of early age of onset and psychotic features. We investigate potential cortical morphology differences associated with this subtype. We analyze, for the first time in bipolar disorders, the sulcal pits, the deepest points in each fold of the cerebral cortex.

METHODS

We extracted the sulcal pits from anatomical MRI among 512 participants gathered from 7 scanning sites. We compared the number of sulcal pits in each hemisphere as well as their regional occurrence and depth between the BD-ND subgroup (N = 184), a subgroup without neurodevelopmental features (BD, N = 77) and a group of healthy controls (HC, N = 251).

RESULTS

In whole brain analysis, BD-ND group have a higher number of sulcal pits in comparison to the BD group. The local analysis revealed, after correction for multiple testing, a higher occurrence of sulcal pits in the left premotor cortex among the BD-ND subgroup compared to the BD and the HC groups.

CONCLUSION

Our findings confirm that BD-ND is associated with a specific brain morphology revealed by the analysis of sulcal pits. These markers may help to better understand neurodevelopment in mood disorder and stratify patients according to a pathophysiological hypothesis.

Real-time fMRI neurofeedback as a new treatment for psychiatric disorders: A meta-analysis

Neurofeedback using real-time functional MRI (RT-fMRI-NF) is an innovative technique that allows to voluntarily modulate a targeted brain response and its associated behavior. Despite promising results in the current literature, its effectiveness on symptoms management in psychiatric disorders is not yet clearly demonstrated. Here, we provide 1) a state-of-art qualitative review of RT-fMRI-NF studies aiming at alleviating clinical symptoms in a psychiatric population; 2) a quantitative evaluation (meta-analysis) of RT-fMRI-NF effectiveness on various psychiatric disorders and 3) methodological suggestions for future studies. Thirty-one clinical trials focusing on psychiatric disorders were included and categorized according to standard diagnostic categories. Among the 31 identified studies, 22 consisted of controlled trials, of which only eight showed significant clinical improvement in the experimental vs. control group after the training. Nine studies found an effect at follow-up on ADHD symptoms, emotion dysregulation, facial emotion processing, depressive symptoms, hallucinations, psychotic symptoms, and specific phobia. Within-group meta-analysis revealed large effects of the NF training on depressive symptoms right after the training (g = 0.81, p < 0.01) and at follow-up (g = 1.19, p < 0.01), as well as medium effects on anxiety (g = 0.44, p = 0.01) and emotion regulation (g = 0.48, p < 0.01). Between-group meta-analysis showed a medium effect on depressive symptoms (g = 0.49, p < 0.01) and a large effect on anxiety (g = 0.77, p = 0.01). However, the between-studies heterogeneity is very high. The use of RT-fMRI-NF as a treatment for psychiatric symptoms is promising, however, further double-blind, multicentric, randomized-controlled trials are warranted.

A multicentric multimodal in vivo microscopy MRI study of bipolar disorder reveals axonal loss and demyelination

Introduction

Bipolar disorder has been repeatedly associated with abnormalities of white matter. However, DTI is intrinsically limited and the precise cellular mechanisms that underlie these alterations remains unknown.

Objectives

Our aim was to investigate microscopical characteristics of white matter using MRI in patients with bipolar and healthy controls.

Methods

77 patients and 71 controls from 3 sites had a T1 structural MRI, a multi-shell HARDI MRI and at one site with a T1-weighted VFA-SPGR acquisition, and a T2 MSME acquisition. The volume fraction and the orientation dispersion was extracted using NODDI from DW images in each site. Myelin Water Fraction was extracted in 33 patients and 36 controls to probe myelin characteristics. White matter bundles were reconstructed using deterministic tractography. Statistical analyses were performed after harmonization by the ComBat algorithm and controlled for age, gender and handedness.

Results

We found significant lower axonal density in patients along the short fibers of the left cingulum, the left anterior arcuate and the left inferior fronto-occipital fasciculus. We found lower mean MWF in patients along the short fibers of the right cingulum, the left inferior fronto-occipital fasciculus, the left anterior arcuate and the splenium of the corpus callosum. We found higher mean orientation dispersion in patients only along the left uncinate fasciculus.

Conclusions

We report alterations of limbic and inter-hemispheric white matter tracts in patients with bipolar disorder reflecting axonal loss, demyelination and architecture alterations. These results contribute to better capture the plurality of the mechanisms involved in bipolar disorder that cannot be deciphered with classical diffusion MRI.

Disclosure

No significant relationships.

What we learn about bipolar disorder from large-scale neuroimaging: Findings and future directions from the ENIGMA Bipolar Disorder Working Group

MRI-derived brain measures offer a link between genes, the environment and behavior and have been widely studied in bipolar disorder (BD). However, many neuroimaging studies of BD have been underpowered, leading to varied results and uncertainty regarding effects. The Enhancing Neuro Imaging Genetics through Meta-Analysis (ENIGMA) Bipolar Disorder Working Group was formed in 2012 to empower discoveries, generate consensus findings and inform future hypothesis-driven studies of BD. Through this effort, over 150 researchers from 20 countries and 55 institutions pool data and resources to produce the largest neuroimaging studies of BD ever conducted. The ENIGMA Bipolar Disorder Working Group applies standardized processing and analysis techniques to empower large-scale meta- and mega-analyses of multimodal brain MRI and improve the replicability of studies relating brain variation to clinical and genetic data. Initial BD Working Group studies reveal widespread patterns of lower cortical thickness, subcortical volume and disrupted white matter integrity associated with BD. Findings also include mapping brain alterations of common medications like lithium, symptom patterns and clinical risk profiles and have provided further insights into the pathophysiological mechanisms of BD. Here we discuss key findings from the BD working group, its ongoing projects and future directions for large-scale, collaborative studies of mental illness.

ENIGMA-DTI: Translating reproducible white matter deficits into personalized vulnerability metrics in cross-diagnostic psychiatric research

The ENIGMA-DTI (diffusion tensor imaging) workgroup supports analyses that examine the effects of psychiatric, neurological, and developmental disorders on the white matter pathways of the human brain, as well as the effects of normal variation and its genetic associations. The seven ENIGMA disorder-oriented working groups used the ENIGMA-DTI workflow to derive patterns of deficits using coherent and coordinated analyses that model the disease effects across cohorts worldwide. This yielded the largest studies detailing patterns of white matter deficits in schizophrenia spectrum disorder (SSD), bipolar disorder (BD), major depressive disorder (MDD), obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), traumatic brain injury (TBI), and 22q11 deletion syndrome. These deficit patterns are informative of the underlying neurobiology and reproducible in independent cohorts. We reviewed these findings, demonstrated their reproducibility in independent cohorts, and compared the deficit patterns across illnesses. We discussed translating ENIGMA-defined deficit patterns on the level of individual subjects using a metric called the regional vulnerability index (RVI), a correlation of an individual's brain metrics with the expected pattern for a disorder. We discussed the similarity in white matter deficit patterns among SSD, BD, MDD, and OCD and provided a rationale for using this index in cross-diagnostic neuropsychiatric research. We also discussed the difference in deficit patterns between idiopathic schizophrenia and 22q11 deletion syndrome, which is used as a developmental and genetic model of schizophrenia. Together, these findings highlight the importance of collaborative large-scale research to provide robust and reproducible effects that offer insights into individual vulnerability and cross-diagnosis features.

Brain aging in major depressive disorder: results from the ENIGMA major depressive disorder working group

Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 samples worldwide. Healthy brain aging was estimated by predicting chronological age (18-75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted "brain age" and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen's d = 0.14, 95% CI: 0.08-0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates.

Decreased emotional reactivity after 3-month socio-affective but not attention- or meta-cognitive-based mental training: A randomized, controlled, longitudinal fMRI study

Meditation-based mental training interventions show physical and mental health benefits. However, it remains unclear how different types of mental practice affect emotion processing at both the neuronal and the behavioural level. In the context of the ReSource project, 332 participants underwent an fMRI scan while performing an emotion anticipation task before and after three 3-month training modules cultivating 1) attention and interoceptive awareness (Presence); 2) socio-affective skills, such as compassion (Affect); 3) socio-cognitive skills, such as theory of mind (Perspective). Only the Affect module led to a significant reduction of experienced negative affect when processing images depicting human suffering. In addition, after the Affect module, participants showed significant increased activation in the right supramarginal gyrus when confronted with negative stimuli. We conclude that socio-affective, but not attention- or meta-cognitive based mental training is specifically effective to improve emotion regulation capabilities when facing adversity.

Lithium prevents grey matter atrophy in patients with bipolar disorder: an international multicenter study

BACKGROUND

Lithium (Li) is the gold standard treatment for bipolar disorder (BD). However, its mechanisms of action remain unknown but include neurotrophic effects. We here investigated the influence of Li on cortical and local grey matter (GM) volumes in a large international sample of patients with BD and healthy controls (HC).

METHODS

We analyzed high-resolution T1-weighted structural magnetic resonance imaging scans of 271 patients with BD type I (120 undergoing Li) and 316 HC. Cortical and local GM volumes were compared using voxel-wise approaches with voxel-based morphometry and SIENAX using FSL. We used multiple linear regression models to test the influence of Li on cortical and local GM volumes, taking into account potential confounding factors such as a history of alcohol misuse.

RESULTS

Patients taking Li had greater cortical GM volume than patients without. Patients undergoing Li had greater regional GM volumes in the right middle frontal gyrus, the right anterior cingulate gyrus, and the left fusiform gyrus in comparison with patients not taking Li.

CONCLUSIONS

Our results in a large multicentric sample support the hypothesis that Li could exert neurotrophic and neuroprotective effects limiting pathological GM atrophy in key brain regions associated with BD.

Will machine learning applied to neuroimaging in bipolar disorder help the clinician? A critical review and methodological suggestions

OBJECTIVES

The existence of anatomofunctional brain abnormalities in bipolar disorder (BD) is now well established by magnetic resonance imaging (MRI) studies. To create diagnostic and prognostic tools, as well as identifying biologically valid subtypes of BD, research has recently turned towards the use of machine learning (ML) techniques. We assessed both supervised ML and unsupervised ML studies in BD to evaluate their robustness, reproducibility and the potential need for improvement.

METHOD

We systematically searched for studies using ML algorithms based on MRI data of patients with BD until February 2019.

RESULT

We identified 47 studies, 45 using supervised ML techniques and 2 including unsupervised ML analyses. Among supervised studies, 43 focused on diagnostic classification. The reported accuracies for classification of BD ranged between (a) 57% and 100%, for BD vs healthy controls; (b) 49.5% and 93.1% for BD vs patients with major depressive disorder; and (c) 50% and 96.2% for BD vs patients with schizophrenia. Reported accuracies for discriminating subjects genetically at risk for BD (either from control or from patients with BD) ranged between 64.3% and 88.93%.

CONCLUSIONS

Although there are strong methodological limitations in previous studies and an important need for replication in large multicentric samples, the conclusions of our review bring hope of future computer-aided diagnosis of BD and pave the way for other applications, such as treatment response prediction. To reinforce the reliability of future results we provide methodological suggestions for good practice in conducting and reporting MRI-based ML studies in BD.

ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries

This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors.

Higher in vivo Cortical Intracellular Volume Fraction Associated with Lithium Therapy in Bipolar Disorder: A Multicenter NODDI Study

BACKGROUND

MRI studies in patients with bipolar disorder have suggested that lithium is associated with grey matter increases that may underlie its therapeutic effects. However, the relationship between grey matter volume and cellular microstructural changes is not straightforward, as modifications of different cellular compartments of grey matter may be involved.

OBJECTIVES

Our aim was to test the hypothesis that dendritic density is higher in patients undergoing lithium therapy than in patients without lithium, using advanced modelling of water diffusion investigated with MRI.

METHOD

We included 41 patients and 40 controls matched for age and gender from two sites. All subjects underwent 3T MRI with 3 shells of diffusion. We used neurite orientation dispersion and density imaging to compare the grey matter neurite density between patients undergoing lithium therapy or not and control subjects.

RESULTS

We found a significant group effect in the left prefrontal region (p = 0.001, Bonferroni corrected): patients without lithium had a lower frontal neurite density than controls (p = 0.009), while those on lithium had a higher mean neurite density than those without (p < 0.001). Patients on lithium were not different from controls (p = 0.08).

CONCLUSIONS

This is the first study to report in vivo evidence of preserved neurite density of the prefrontal cortex in humans associated with lithium intake. Changes of intracellular volume fraction are thought to reflect changes of grey matter microstructural organization. This reinforces the hypothesis of lithium having a positive effect on the neuronal compartment in humans.

Food-Cal: development of a controlled database of high and low calorie food matched with non-food pictures

BACKGROUND

Industrialization has led to more varied and attractive high-calorie foods. Health problems such as obesity and diabetes are partially attributed to eating-related self-regulation difficulties that may be caused by increasingly frequent cues for highly palatable foods. Research studies aim at understanding the factors underlying responses to food cues. This has led to the development of food stimuli databases. However, they present some limitations.

OBJECTIVES

This study aimed at providing a controlled set of pictures, including 40 food pictures with high- and low-calorie stimuli, matched with 40 non-food pictures. The second objective was to provide a ready-to-use database with normative data regarding responses and associations between demographic, anthropometric and eating-related characteristics, and picture ratings.

PARTICIPANTS

A sample of 264 participants rated the total set of pictures.

MEASURES

Attractiveness, arousal and palatability were assessed for each picture, as well as participant's current type of diet, BMI, hunger levels and eating behaviors (uncontrolled and emotional eating).

RESULTS

Image characteristics (shape, colors, luminance) were comparable between food and matched non-food pictures. Positive correlations were found between hunger levels and attractiveness, arousal and palatability of food. Uncontrolled and emotional eating was positively correlated with high-calorie food palatability, and uncontrolled eating was positively correlated with high-calorie food attractiveness. Participants who did not report any specific diet rated high-calorie foods as more attractive and arousing, whereas vegan and vegetarian participants assessed low-calorie foods as more attractive and palatable.

CONCLUSION

The Food-Cal controlled set of picture database can be considered as a useful tool for experimental research.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Cerebellar parcellation in schizophrenia and bipolar disorder

OBJECTIVE

The cerebellum is involved in cognitive processing and emotion control. Cerebellar alterations could explain symptoms of schizophrenia spectrum disorder (SZ) and bipolar disorder (BD). In addition, literature suggests that lithium might influence cerebellar anatomy. Our aim was to study cerebellar anatomy in SZ and BD, and investigate the effect of lithium.

METHODS

Participants from 7 centers worldwide underwent a 3T MRI. We included 182 patients with SZ, 144 patients with BD, and 322 controls. We automatically segmented the cerebellum using the CERES pipeline. All outputs were visually inspected.

RESULTS

Patients with SZ showed a smaller global cerebellar gray matter volume compared to controls, with most of the changes located to the cognitive part of the cerebellum (Crus II and lobule VIIb). This decrease was present in the subgroup of patients with recent-onset SZ. We did not find any alterations in the cerebellum in patients with BD. However, patients medicated with lithium had a larger size of the anterior cerebellum, compared to patients not treated with lithium.

CONCLUSION

Our multicenter study supports a distinct pattern of cerebellar alterations in SZ and BD.

Neurodevelopmental subtypes of bipolar disorder are related to cortical folding patterns: An international multicenter study

OBJECTIVES

Brain sulcation is an indirect marker of neurodevelopmental processes. Studies of the cortical sulcation in bipolar disorder have yielded mixed results, probably due to high variability in clinical phenotype. We investigated whole-brain cortical sulcation in a large sample of selected patients with high neurodevelopmental load.

METHODS

A total of 263 patients with bipolar disorder I and 320 controls were included in a multicentric magnetic resonance imaging (MRI) study. All subjects underwent high-resolution T1-weighted brain MRI. Images were processed with an automatized pipeline to extract the global sulcal index (g-SI) and the local sulcal indices (l-SIs) from 12 a priori determined brain regions covering the whole brain. We compared l-SI and g-SI between patients with and without early-onset bipolar disorder and between patients with and without a positive history of psychosis, adjusting for age, gender and handedness.

RESULTS

Patients with early-onset bipolar disorder had a higher l-SI in the right prefrontal dorsolateral region. Patients with psychotic bipolar disorder had a decreased l-SI in the left superior parietal cortex. No group differences in g-SI or l-SI were found between healthy subjects and the whole patient cohort. We could replicate the early-onset finding in an independent cohort.

CONCLUSIONS

Our work suggests that bipolar disorder is not associated with generalized abnormalities of sulcation, but rather with localized changes of cortical folding restricted to patients with a heavy neurodevelopmental loading. These findings support the hypothesis that bipolar disorder is heterogeneous but may be disentangled using MRI, and suggest the need for investigations into neurodevelopmental deviations in the disorder.

Stimulation of subgenual cingulate area decreases limbic top-down effect on ventral visual stream: A DBS-EEG pilot study

Deep brain stimulation (DBS) of the subgenual cingulate gyrus (area CG25) is beneficial in treatment resistant depression. Though the mechanisms of action of Cg25 DBS remain largely unknown, it is commonly believed that Cg25 DBS modulates limbic activity of large networks to achieve thymic regulation of patients. To investigate how emotional attention is influenced by Cg25 DBS, we assessed behavioral and electroencephalographic (EEG) responses to an emotional Stroop task in 5 patients during ON and OFF stimulation conditions. Using EEG source localization, we found that the main effect of DBS was a reduction of neuronal responses in limbic regions (temporal pole, medial prefrontal and posterior cingulate cortices) and in ventral visual areas involved in face processing. In the dynamic causal modeling (DCM) approach, the changes of the evoked response amplitudes are assumed to be due to changes of long range connectivity induced by Cg25 DBS. Here, using a simplified neural mass model that did not take explicitly into account the cytoarchitecture of the considered brain regions, we showed that the remote action of Cg25 DBS could be explained by a reduced top-down effective connectivity of the amygdalo-temporo-polar complex. Overall, our results thus indicate that Cg25 DBS during the emotional Stroop task causes a decrease of top-down limbic influence on the ventral visual stream itself, rather than a modulation of prefrontal cognitive processes only. Tuning down limbic excitability in relation to sensory processing might be one of the biological mechanisms through which Cg25 DBS produces positive clinical outcome in the treatment of resistant depression.

Fronto-striatal organization: Defining functional and microstructural substrates of behavioural flexibility

Discrete yet overlapping frontal-striatal circuits mediate broadly dissociable cognitive and behavioural processes. Using a recently developed multi-echo resting-state functional MRI (magnetic resonance imaging) sequence with greatly enhanced signal compared to noise ratios, we map frontal cortical functional projections to the striatum and striatal projections through the direct and indirect basal ganglia circuit. We demonstrate distinct limbic (ventromedial prefrontal regions, ventral striatum – VS, ventral tegmental area – VTA), motor (supplementary motor areas – SMAs, putamen, substantia nigra) and cognitive (lateral prefrontal and caudate) functional connectivity. We confirm the functional nature of the cortico-striatal connections, demonstrating correlates of well-established goal-directed behaviour (involving medial orbitofrontal cortex – mOFC and VS), probabilistic reversal learning (lateral orbitofrontal cortex – lOFC and VS) and attentional shifting (dorsolateral prefrontal cortex – dlPFC and VS) while assessing habitual model-free (SMA and putamen) behaviours on an exploratory basis. We further use neurite orientation dispersion and density imaging (NODDI) to show that more goal-directed model-based learning (MB_c) is also associated with higher mOFC neurite density and habitual model-free learning (MF_c) implicates neurite complexity in the putamen. This data highlights similarities between a computational account of MF_c and conventional measures of habit learning. We highlight the intrinsic functional and structural architecture of parallel systems of behavioural control.

Cerebral Correlates of Abnormal Emotion Conflict Processing in Euthymic Bipolar Patients: A Functional MRI Study

BACKGROUND

Patients with bipolar disorder experience cognitive and emotional impairment that may persist even during the euthymic state of the disease. These persistent symptoms in bipolar patients (BP) may be characterized by disturbances of emotion regulation and related fronto-limbic brain circuitry. The present study aims to investigate the modulation of fronto-limbic activity and connectivity in BP by the processing of emotional conflict.

METHODS

Fourteen euthymic BP and 13 matched healthy subjects (HS) underwent functional magnetic resonance imaging (fMRI) while performing a word-face emotional Stroop task designed to dissociate the monitoring/generation of emotional conflict from its resolution. Functional connectivity was determined by means of psychophysiological interaction (PPI) approach.

RESULTS

Relative to HS, BP were slower to process incongruent stimuli, reflecting higher amount of behavioral interference during emotional Stroop. Furthermore, BP showed decreased activation of the right dorsolateral prefrontal cortex (DLPFC) during the monitoring and a lack of bilateral amygdala deactivation during the resolution of the emotional conflict. In addition, during conflict monitoring, BP showed abnormal positive connectivity between the right DLPFC and several regions of the default mode network.

CONCLUSIONS

Overall, our results highlighted dysfunctional processing of the emotion conflict in euthymic BP that may be subtended by abnormal activity and connectivity of the DLPFC during the conflict monitoring, which, in turn, leads to failure of amygdala deactivation during the resolution of the conflict. Emotional dysregulation in BP may be underpinned by a lack of top-down cognitive control and a difficulty to focus on the task due to persistent self-oriented attention.

Modulation of fronto-limbic activity by the psychoeducation in euthymic bipolar patients. A functional MRI study

Bipolar disorders (BD) are mainly characterized by emotional and cognitive processing impairment. The cerebral substrate explaining BD impairment and the action mechanisms of therapies are not completely understood, especially for psychosocial interventions. This fMRI study aims at assessing cerebral correlates of euthymic bipolar patients (EBP) before and after psychoeducation therapy. Sixteen EBP and 16 matched healthy subjects (HS) performed a word-face emotional Stroop task in two separate fMRI sessions at 3-month interval. Between fMRI sessions, EBP underwent psychoeducation. Before psychoeducation, the comparison of EBP vs. HS in fMRI data revealed (a) significant decreased activity of cognitive control regions such as bilateral inferior and left superior frontal gyri, right insula, right fusiform gyrus and bilateral occipital gyri and (b) significant increased activity of emotion-related processing regions such as bilateral hippocampus, parahippocampal gyri and the left middle temporal gyrus. After psychoeducation, EBP showed significant clinical improvement, increased activity of inferior frontal gyri and a tendency toward decreased activity of right hippocampus and parahippocampal gyrus. These results suggest that the imbalance between cognitive control and emotion processing systems characterizing BD acute episodes may persist during euthymic periods. Moreover, this imbalance may be improved by psychoeducation, which enhances the cognitive control and modulates emotional fluctuations in EBP.

Misalignment of total ankle components can induce high joint contact pressures

BACKGROUND

A major cause of the limited longevity of total ankle replacements is premature polyethylene component wear, which can be induced by high joint contact pressures. We implemented a computational model to parametrically explore the hypothesis that intercomponent positioning deviating from the manufacturer's recommendations can result in pressure distributions that may predispose to wear of the polyethylene insert. We also investigated the hypothesis that a modern mobile-bearing design may be able to better compensate for imposed misalignments compared with an early two-component design.

METHODS

Two finite element models of total ankle replacement prostheses were built to quantify peak and average contact pressures on the polyethylene insert surfaces. Models were validated by biomechanical testing of the two implant designs with use of pressure-sensitive film. The validated models were configured to replicate three potential misalignments with the most

CLINICAL RELEVANCE

version of the tibial component, version of the talar component, and relative component rotation of the two-component design. The misalignments were simulated with use of the computer model with physiologically relevant boundary loads.

RESULTS

With use of the manufacturer's guidelines for positioning of the two-component design, the predicted average joint contact pressures exceeded the yield stress of polyethylene (18 to 20 MPa). Pressure magnitudes increased as implant alignment was systematically deviated from this reference position. The three-component design showed lower-magnitude contact pressures in the standard position (<10 MPa) and was generally less sensitive to misalignment. Both implant systems were sensitive to version misalignment.

CONCLUSIONS

In the tested implants, a highly congruent mobile-bearing total ankle replacement design yields more evenly distributed and lower-magnitude joint contact pressures than a less congruent design. Although the mobile-bearing implant reduced susceptibility to aberrant joint contact characteristics that were induced by misalignment, predicted average contact stresses reached the yield stress of polyethylene for imposed version misalignments of >5 degrees.

The role of the subscapularis in preventing anterior glenohumeral subluxation in the abducted, externally rotated position of the arm

BACKGROUND

Current literature suggests that the subscapularis muscle is the main active stabilizer when the humerus is abducted and externally rotated. Conservative treatment of anterior shoulder instability therefore aims at strengthening this muscle. Empirical models, however, have questioned the role of the subscapularis muscle as it has been observed to potentially support dislocation of the subluxated humeral head.

METHODS

Ten human shoulders were loaded with an anterior dislocating force and the effect of different subscapularis tensions on humeral translation was measured with the Motion Analysis system, for the abducted and externally rotated arm and neutral positions. Also, lines of action of the subscapularis segments were measured on a 3D epoxy model.

FINDINGS

Shoulders in which the humeral head migrated antero-superiorly under an external antero-inferior load were observed to dislocate under simulated active subscapularis tension in both positions. In contrast, shoulders in which the head migrated antero-inferiorly remained stable. Twice as many specimens dislocated in the abducted - externally rotated position than in the neutral position. The change in line of action of the subscapularis may account for this change.

INTERPRETATION

Exercises alone are unlikely to be adequate for all patients with anterior instability symptoms. Passive motion pattern of the humeral head might serve as an indicator as to whether the effect of strengthening the subscapularis might stabilize a shoulder without further operation. Development of a clinical test based on these findings might differentiate the non-operative from operative candidates among patients presenting with anterior instability of the shoulder.

Uncemented short-length diaphyseal segmental replacement prosthesis fixation--finite element analysis and long-term results

INTRODUCTION

Extensively porous coated segmental replacement prostheses with intramedullary cementless fixation to bone over the whole length of stem often exhibit resorption of the surrounding bone due to stress-shielding. This makes them particularly susceptible to aseptic loosening.

STUDY

A finite element analysis of the state of loading of a short-length fixation in a new prosthetic stem design has shown a definite advantage over long-length fixation. The stress pattern within the bone surrounding the prosthesis confirmed that shortening of the ongrowth area in length increases the stress values at the resection level significantly. This stem (Endlock) has been used for diaphyseal anchorage in the treatment of tumors in combination with an artificial joint of proven design in order to reduce stress shielding.

RESULTS

No Endlock stem fractures or aseptic loosenings were observed at recent follow-up. The early clinical results comply with the theoretical assumptions.

CONCLUSIONS

A short-length fixation system based on intramedullary anchorage of segmental replacement endoprostheses would possibly support physiologic adaptive processes more than fixation over the full length of the stem.

L’information du sujet schizophrène en pratique clinique : données actuelles

Social isolation has got to be one of the greatest losses in schizophrenia. For many authors, people with schizophrenia can have no friends, no spouse, and sometimes no family. Two thirds of patients with schizophrenia return to their parents' house after discharge from a hospital for the first psychosi episode. Family members generally receive very little education as to what they can expect. They may not know the importance of medication compliance. Family members are the primary victims of violence from psychotic individuals, usually their own son or daughter, and most families cannot believe their own son or daughter would be capable of such a thing. Although families are usually the main care givers at the beginning of schizophrenia they often find their experience very frustrating for a number of reasons, and relationships suffer. Family education and support have been shown to improve outcomes considerably and family education is the second strongest factor in relapse prevention. Without education and good relapse prevention families often burst out. Most of the homeless mentally ill in downtown city cores have lost their family relationships. It is not a reflection on their families so much as the lack of adequate treatment and support. The families tried and tried and lost their ill relative. A patient writes: "My father lives just outside of Monaco. My mother developed Alzheimer's a couple of years ago or so and with a series of mild strokes died recently. I haven't seen either of them very much in the last fifteen years. I have a sister, Nicole, who also lives in Paris. I lost those relationships to some degree over the years. I am rebuilding them now. Enter the professional friend, the case manager, usually in cases where the individual is quite disabled by schizophrenia and/or at considerable risk of relapse, and usually when the individual has lost their family relationships to some degree. I had a case manager for several years and always looked forward to her visits. Case managers help negotiate compliance to medication, housing, meaningful activity, substance abuse, poverty, isolation, and everything else living in the community can throw at you. Without a spouse you tend to spend a lot of time alone. One of the main reasons Marie-Claude and I moved in with each other was that neither of us was enjoying living alone. It was very romantic at first but now we are just friends who see less and less of each other. I suspect schizophrenia interferes with the quality and depth of relationships you have with other people. Amongst the people I know, schizophrenia has meant a pretty solitary life of poverty. I have a lot of acquaintances, and colleagues, but few close friends when not at work. Over the last ten years of living with schizophrenia on medication it is celibacy that has hurt the most. It saps the life out of you, your self confidence, your self esteem. In some Scandinavian countries and Holland disabled people are allowed monthly visits by state approved sex workers. To me that is only common sense. To live without sex is unnatural and can only cause emotional suffering. We don't recognize the importance of quality sexual experience in keeping people healthy and happy in France. That doesn't mean it isn't I have a pretty high profile in my community through the meaningful activity I do. From having a half dozen names and faces to remember, I now have what seems like hundreds. I have a lot of trouble remembering people's names and faces. I am still meeting new people but I'm rarely invited to socialize with any after work. They have families, full time jobs, kids, cars, cottages, etc. My life at home is pretty solitary. It's a nuisance to travel across the city to visit people. There are few people that I share a similar background with. Since people with schizophrenia tend to have trouble learning new things, and change very little as a result, we tend to have trouble making new friends. People with schizophrenia can come alive talking about things in the past before they became ill. It's as if their life grinded to halt when they became sick. I'm stuck in the mid seventies, and that's the music I like. Everybody I know with schizophrenia is quite isolated socially and I don't really know why. That is especially true for the older people in my age group. Younger people seem to be doing much better. Many still live with their parents. Most older people live alone. There is also the odd person who recovers well, returns to a career, and marries someone without schizophrenia. In cases where marriage predates the onset of schizophrenia, the outcome is often divorce although women are more likely to stick with their husbands with schizophrenia than vice versa, especially if there are already children. I hope the next generation who appears to be less disabled survives better than people of my age with schizophrenia. The goal of community integration is one that requires: more effective treatments and/or more financial support and/or a compassionate non-discriminating community. The combination of early diagnosis and atypical medications will change the face of schizophrenia. I'm not expecting more financial support from the government, but many more people with schizophrenia will start working again instead. Their social networks will develop but social networks are probably the hardest hit in schizophrenia. It's better that you never lose your friends in the first place". This testimony shows how the information of the schizophrenic patient is necessary, and underlines the importance of the relationships between the patient and his family. Our article insists on this theme, rarely developed in the literature.

[Characteristics of patients hospitalized in a specialized hospital center after after attempted suicide]

Authors have counted, during a period of one year, the totality of patients having been admitted to the Centre Hospitalier Spécialisé de la Savoie (Chambéry) following a volunteer medicinal intoxication; 227 patients have been thus included, this type of acting out concerning third more women than men. The higher impact is found in young adults (20-40 years). Professional inactivity appears as a favoring factor, while the way of life (bachelor or in couple) does not seem to have consequence on the frequency of occurrence of the suicidal attempts. Relapses are numerous, and happen in most cases during the year. Concerning used medicines, they have been generally prescribed by a practitioner or a psychiatrist. The prominent fact is the presence of a very short period between the prescription, the deliverance of the medicine and the acting out. Plurimedicinal intoxications are increasingly frequent, with often concurrent absorption of alcohol. The diminution of the use of barbiturics in ambulatory medicine to the profit of other molecules, and especially the benzodiazepines, has reduced the frequency of their use in volunteers medicinal intoxications. Benzodiazepines are the most employed medicines in this type of acting out. This epidemiological and toxicological study confirms that used substances during volunteer medicinal intoxication are a reflection of the general medicinal consumption.

[Restraint and seclusion in psychiatry: review and prospects]

In this article, the authors reviewed the literature published since 1965 concerning restraint and seclusion. They synthesized the contents of the articles reviewed using the categories of indications and contraindications; rates of seclusion and restraint as well as demographic, clinical, and environmental factors that affect these rates; effects on patients and staff; implementation; and training. The literature on restraint and seclusion supports the following: 1) Seclusion and restraint are basically efficacious in preventing injury and reducing agitation; 2) It is nearly impossible to operate a program for severely symptomatic individuals without some form of seclusion or physical or mechanical restraint; 3) Demographic and clinical factors have limited influence on rates of restraint and seclusion; 4) Training in prediction and prevention of violence, in self-defense, and in implementation of restraint and/or seclusion is valuable in reducing rates and untoward effects; 5) Studies comparing well-defined training programs have potential usefulness.

[Apropos of using patient isolation in psychiatry: point of view of nurses]

Seclusion continues to be used in the care of acutely disturbed psychiatric patients despite often emotionally charged debate about its appropriateness within mental health services. Powerful legal and moral arguments about the use of seclusion emphasize an urgent need to critically examine its role in the care of mentally ill people. This paper examines the use of seclusion on psychiatric departments in the management of acutely disturbed patients: 36 psychiatric nurses working in 6 departments in a specialized hospital (the CHS de la Savoie, in Chambery) were interviewed in relation to their perceptions of the role of seclusion. Data were analysed using grounded theory methodology revealing the core conceptual category "controlling" and two sub-categories "watching out for" and "watching over". Seclusion was found to be used as an adjunctive treatment in the care of individuals considered to be "out of control". Clinicians expressed comfort with the use of seclusion, citing a strict protocol that provided parameters for its use. While expert therapeutic interventions were described by clinicians, they are contextualized within a framework of power and control--a framework that stands in stark contrast to contemporary philosophies of nursing care, providing impetus for a reconsideration of the use of constraining practices in the care of mentally ill people.

[Vulnerability to schizophrenia. III: Importance and limits of the Identical Pairs Continuous Performance Test]

Since several investigations have shown attentional deficits both in patients with schizophrenia and in subjects at high risk for schizophrenia, these deficits could be valuable vulnerability markers for schizophrenia. The aim of this study was to investigate wether non psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs (CPT-IP) version. The study subjects were 25 schizophrenic probands, 50 of their first-degree relatives and 46 normal controls. For each subject, attention was assessed during 6 experimental conditions (2 standard, 2 slow, 2 easy conditions) of visual stimuli (digit-numbers and shapes). In each of the six conditions, the value of the sensitive index d' in the first-degree relative group was at an intermediate level between the patient and control groups. Moreover, in the standard shape condition, the d' value was significantly lower in the schizophrenic and in the relative groups than in the control group. This deficit was all the more interesting since it was not explained by a deficit in general intellectual abilities or by psychopathology such as anxiety or depression. Furthermore, the schizophrenic patients made more random errors in the standard and in the slow number conditions than both other groups. All groups improved their performance when the stimulus duration increased and when the processing load decreased. As a conclusion, this investigation seems: 1) to confirm the existence of an attentional deficit in the first-degree relatives of patients with schizophrenia; 2) to demonstrate the interest of the CPT-IP to detect this deficit. It must be emphasized that in order to detect the deficit, one only needs to explore the standard shape condition and that under such circumstances, the CPT-IP test has the advantage of being less time consuming than tests used in previous studies.

Examiner agreement on periodontal indices during dental surveys of elders

Indices used to evaluate periodontal health have been widely accepted in epidemiological studies, yet their reliability cannot be guaranteed. The aim of this study was to evaluate the reliability of periodontal indices applied on elders. 19 elderly subjects, 73-years-old on average, were examined at a 1st appointment by 2 independent examiners. They were re-examined 2 weeks later during a 2nd session. The examinations were performed in a dental chair with good illumination. Periodontal health was evaluated using the community periodontal index of treatment need, and tooth mobility was evaluated using 2 different indices. Inter and intra-examiner agreements were evaluated using kappa statistics. Taken as an overall measurement, the CPITN was a reliable assessment of periodontal treatment need in elders. Disagreement occurred mainly on the evaluation of bleeding and shallow pockets. The detection of fairly mobile teeth was reliable; however, the performance of the more sensitive scale was deceptive. it seems that, in the case of tooth mobility, a choice has to be made between sensitivity or reproducibility. It can be concluded that examiners should be trained carefully since the reliability of the CPITN and tooth mobility evaluation were good but close to a critical level for which an agreement is classified as poor.

Examiner agreement on caries detection and plaque accumulation during dental surveys of elders

Indices used to evaluate plaque accumulation and coronal caries have been widely accepted in epidemiological studies, yet their reliability cannot be guaranteed. The aim of this study was to evaluate the reliability of clinical criteria used in coronal and root caries diagnosis and oral hygiene evaluation as applied in elders. Nineteen elderly subjects, 73 years old on average, were examined at a first appointment by two independent examiners. They were re-examined two weeks later. Plaque accumulation was evaluated using the Plaque Index (PI) and coronal and root caries were detected according to the WHO criteria and Fejerskov et al. (1991), respectively. Recurrent caries was recorded as recommended by WHO and by probing at the interface tooth-restoration. Inter- and intra-examiner agreement was evaluated using kappa statistics. The PI score showed good reliability except for examiner b, for whom a simplification of the 4-point scale in 3-point scale improved significantly the reliability. The prevalence of coronal caries was very low and intra- and inter-examiner agreement was poor. Most of the root caries lesions were covered by plaque and the kappa values indicated only poor agreement. Recurrent caries were found with good agreement using WHO criteria but the detection with the probe was not reliable. In conclusion, it seems that examiners should be trained carefully to maximise their reliability and that plaque should be removed to obtain reliable diagnoses of caries. Retraining and calibration may be necessary for surveys continuing over a long period.